gravitywikiaorg-20200223-history
Silicate minerals
The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group. Silicate minerals all contain silicon and oxygen. Nesosilicates or orthosilicates Nesosilicates, or orthosilicates, have isolated (insular) SiO44− tetrahedra that are connected only by interstitial cations. *Phenacite group **Phenacite - Be2SiO4 **Willemite - Zn2SiO4 *Olivine group **Forsterite - Mg2SiO4 **Fayalite - Fe2SiO4 *Garnet group **Pyrope - Mg3Al2( )3 **Almandine - Fe3Al2( )3 **Spessartine - Mn3Al2( )3 **Grossular - Ca3Al2( )3 **Andradite - Ca3Fe2( )3 **Uvarovite - Ca3Cr2( )3 **Hydrogrossular - Ca3Al2Si2O8(SiO4)3-m(OH)4m *Zircon group **Zircon - ZrSiO4 **Thorite - (Th,U)SiO4 crystals (unknown scale)]] *Al2SiO5 group **Andalusite - Al2SiO5 **Kyanite - Al2SiO5 **Sillimanite - Al2SiO5 **Dumortierite - Al6.5-7BO3(SiO4)3(O,OH)3 **Topaz - Al2SiO4(F,OH)2 **Staurolite - Fe2Al9(SiO4)4(O,OH)2 *Humite group - (Mg,Fe)7(SiO4)3(F,OH)2 **Norbergite - Mg3(SiO4)(F,OH)2 **Chondrodite - Mg5(SiO4)(F,OH)2 **Humite - Mg7(SiO4)(F,OH)2 **Clinohumite - Mg9(SiO4)(F,OH)2 *Datolite - CaBSiO4(OH) *Titanite - CaTiSiO5 *Chloritoid - (Fe,Mg,Mn)2Al4Si2O10(OH)4 Sorosilicates Sorosilicates have isolated double tetrahedra groups with (Si2O7)6− or a ratio of 2:7. *Hemimorphite (calamine) - Zn4(Si2O7)(OH)2·H2O *Lawsonite - CaAl2(Si2O7)(OH)2·H2O *Ilvaite - CaFe2+2Fe3+O(Si2O7)(OH) *Epidote group (has both (SiO4)4− and (Si2O7)6− groups) **Epidote - Ca2(Al,Fe)3O(SiO4)(Si2O7)(OH) **Zoisite - Ca2Al3O(SiO4)(Si2O7)(OH) **Clinozoisite - Ca2Al3O(SiO4)(Si2O7)(OH) **Tanzanite - Ca2Al3O(SiO4)(Si2O7)(OH) **Allanite - Ca(Ce,La,Y,Ca)Al2(Fe2+,Fe3+)O(SiO4)(Si2O7)(OH) **Dollaseite-(Ce) - CaCeMg2AlSi3O11F(OH) *Vesuvianite (idocrase) - Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4 Cyclosilicates Cyclosilicates, or ring silicates, have linked tetrahedra with (SixO3x)2x- or a ratio of 1:3. These exist as 3-member (Si3O9)6-, 4-member (Si4O12)8- and 6-member (Si6O18)12- rings. * 3-member ring ** Benitoite - BaTi(Si3O9) * 4-member ring **Axinite - (Ca,Fe,Mn)3Al2(BO3)(Si4O12)(OH) * 6-member ring **Beryl/Emerald - Be3Al2(Si6O18) **Cordierite - (Mg,Fe)2Al3(Si5AlO18) **Tourmaline - (Na,Ca)(Al,Li,Mg)3-(Al,Fe,Mn)6(Si6O18)(BO3)3(OH)4 Inosilicates Inosilicates, or chain silicates, have interlocking chains of silicate tetrahedra with either SiO3, 1:3 ratio, for single chains or Si4O11, 4:11 ratio, for double chains. Single chain inosilicates *Pyroxene group **Enstatite - orthoferrosilite series ***Enstatite - MgSiO3 ***Ferrosilite - FeSiO3 **Pigeonite - Ca0.25(Mg,Fe)1.75Si2O6 **Diopside - hedenbergite series ***Diopside - CaMgSi2O6 ***Hedenbergite - CaFeSi2O6 ***Augite - (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 **Sodium pyroxene series ***Jadeite - NaAlSi2O6 ***Aegirine (Acmite) - NaFe3+Si2O6 **Spodumene - LiAlSi2O6 *Pyroxenoid group **Wollastonite - CaSiO3 **Rhodonite - MnSiO3 **Pectolite - NaCa2(Si3O8)(OH) Double chain inosilicates *Amphibole group **Anthophyllite - (Mg,Fe)7Si8O22(OH)2 **Cumingtonite series ***Cummingtonite - Fe2Mg5Si8O22(OH)2 ***Grunerite - Fe7Si8O22(OH)2 **Tremolite series ***Tremolite - Ca2Mg5Si8O22(OH)2 ***Actinolite - Ca2(Mg,Fe)5Si8O22(OH)2 **Hornblende - (Ca,Na)2-3(Mg,Fe,Al)5Si6(Al,Si)2O22(OH)2 **Sodium amphibole group ***Glaucophane - Na2Mg3Al2Si8O22(OH)2 ***Riebeckite (asbestos) - Na2Fe2+3Fe3+2Si8O22(OH)2 ***Arfvedsonite - Na3(Fe,Mg)4FeSi8O22(OH)2 Phyllosilicates Phyllosilicates (from Greek φύλλον phyllon, leaf), or sheet silicates, form parallel sheets of silicate tetrahedra with Si2O5 or a 2:5 ratio. *Serpentine group **Antigorite - Mg3Si2O5(OH)4 **Chrysotile - Mg3Si2O5(OH)4 **Lizardite - Mg3Si2O5(OH)4 *Clay mineral group **Halloysite - Al2Si2O5(OH)4 **Kaolinite - Al2Si2O5(OH)4 **Illite - (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10(OH)2,(H2O) **Montmorillonite - (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·''n''H2O **Vermiculite - (MgFe,Al)3(Al,Si)4O10(OH)2·4H2O **Talc - Mg3Si4O10(OH)2 **Palygorskite - (Mg,Al)2Si4O10(OH)·4(H2O) **Pyrophyllite - Al2Si4O10(OH)2 *Mica group **Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2 **Muscovite - KAl2(AlSi3O10)(OH)2 **Phlogopite - KMg3Si4O10(OH)2 **Lepidolite - K(Li,Al)2-3(AlSi3O10)(OH)2 **Margarite - CaAl2(Al2Si2O10)(OH)2 **Glauconite - (K,Na)(Al,Mg,Fe)2(Si,Al)4O10(OH)2 *Chlorite group **Chlorite - (Mg,Fe)3(Si,Al)4O10(OH)2•(Mg,Fe)3(OH)6 Tectosilicates Tectosilicates, or "framework silicates", have a three-dimensional framework of silicate tetrahedra with SiO2 or a 1:2 ratio. This group comprises nearly 75% of the crust of the Earth. Tectosilicates, with the exception of the quartz group, are aluminosilicates. ]] Ferroan Anorthosite #60025 (Plagioclase Feldspar). Collected by Apollo 16 from the Lunar Highlands near Descartes Crater. ]] *Quartz group **Quartz - SiO2 **Tridymite - SiO2 **Cristobalite - SiO2 *Feldspar group **Alkali-feldspars ***Potassium-feldspars ****Microcline - KAlSi3O8 ****Orthoclase - KAlSi3O8 ****Sanidine - KAlSi3O8 ***Anorthoclase - (Na,K)AlSi3O8 **Plagioclase feldspars ***Albite - NaAlSi3O8 ***Oligoclase - (Na,Ca)(Si,Al)4O8 (Na:Ca 4:1) ***Andesine - (Na,Ca)(Si,Al)4O8 (Na:Ca 3:2) ***Labradorite - (Na,Ca)(Si,Al)4O8 (Na:Ca 2:3) ***Bytownite - (Na,Ca)(Si,Al)4O8 (Na:Ca 1:4) ***Anorthite - CaAl2Si2O8 *Feldspathoid group **Nosean - Na8Al6Si6O24(SO4) **Cancrinite - Na6Ca2(CO3,Al6Si6O24).2H2O **Leucite - KAlSi2O6 **Nepheline - (Na,K)AlSiO4 **Sodalite - Na8(AlSiO4)6Cl2 ***Hauyne - (Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2 **Lazurite - (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2 *Petalite - LiAlSi4O10 *Scapolite group **Marialite - Na4(AlSi3O8)3(Cl2,CO3,SO4) **Meionite - Ca4(Al2Si2O8)3(Cl2CO3,SO4) *Analcime - NaAlSi2O6•H2O *Zeolite group **Natrolite - Na2Al2Si3O10•2H2O **Chabazite - CaAl2Si4O12•6H2O **Heulandite - CaAl2Si7O18•6H2O **Stilbite - NaCa2Al5Si13O36•17H2O References * * * * External links *Mineral.galleries *Minerals.net *Mindat.org, Dana classification *Webmineral.com Category:Minerals * de:Silikate et:Silikaadid eo:Silikatmineraloj fr:Silicate hr:Silikati he:מינרלים סיליקטיים lv:Silikātu minerāls lt:Silikatai ja:ケイ酸塩鉱物 pt:Silicato (minerais) fi:Silikaattimineraali sv:Silikatmineral